1. Field of the Invention
The present system relates to a modular adaptive gun having an upper receiver assembly for cooperatively engaging a lower receiver assembly to allow the firing of a projectile from the gun.
2. Description of Related Art
Typically, a rifle includes a trigger, a hammer, and a barrel. The round is positioned in the barrel, and when the trigger is pulled, the hammer fires the round through the barrel. One type of rifle is an M16-style rifle that features a gas-operated bolt and bolt carrier system as disclosed in U.S. Pat. No. 2,951,424, issued to Eugene M. Stoner on Sep. 6, 1960, hereby expressly incorporated by reference. The M16-style rifle is the weapon used by many military and civilian police forces today.
Typically, M16-style rifles include a lower receiver that houses the trigger and hammer, and an upper receiver that houses the barrel, bolt, and bolt carrier. The lower receiver and the upper receiver are detachably coupled together using a coupling mechanism, so that the rifle can be moved with relative ease between an assembled position suited for firing, and a disassembled position suited for cleaning the rifle and for repairing its internal parts. A conventional takedown system features front and rear pins slidably positioned in the lower receiver, and corresponding front and rear connector tabs extending from the upper receiver. A distance between the pins on the lower receiver corresponds to a distance between the connector tabs on the upper receiver, so that the pins can be pushed into and out of the connector tabs to selectively attach and detach the upper and lower receivers.
In some cases, the upper receiver can be substituted with a different upper receiver, such as a close quarters battle receiver (CQBR), which is a replacement upper receiver having a relatively shorter barrel. Like the conventional upper receiver, the CQBR has connector tabs that are separated by a distance corresponding to the distance between the pins on the lower receiver, so that the CQBR can be coupled to the lower receiver. In the field, the CQBR is employed during indoor operations or other operations in which a longer barrel rifle may be cumbersome to maneuver.
Therefore, the need exists for an upper receiver that can cooperate with a variety of lower receivers, wherein the operating or performance characteristics of the upper receiver can be independent of the lower receiver. The need also exists for an upper receiver that can be configured to provide a predetermined operation for exposing a motive gas to a projectile in a firing chamber independent of the tuning or adjustment or feel of a trigger used by the operator to fire the gun.